Machine tool transmission and control



May 28, 1940. F. A. PARSONS MACHINE TOOL TRANSMISSION AND CONTROL Filed Dec. 18, 1936 5 Sheets-Sheet 1 fwwq ATTORNEY I INVENTOR QM xww May 28, 1940.

F. A. PAhsous MACHINE TOOL TRANSMISSION AND CONTROL Filed Dec. 18, 1936 5 Sheets-Sheet 2 INVENT ATTORNEY May 28, 1940. F. A. PARSONS MACHINE TOOL TRANSMISSION AND CONTROL 5 Sheets-Sheet 3 Filed Dec.

ATTORNEY May 28, 1940. F. A. PARSONS MACHINE TOOL TRANSMISSION AND CONTROL Filed Dec. 18, 1956 5 Sheets-Sheet 4 R a W ATTORNEY INVENTO F. A. PARSONS MACHINE TOOL TRANSMISSION AND CONTROL May 28, 1940.

v 5 Sheets-Sheet 5 Filed Dec. 18, 1936 INVENTOR ATTORNEY Patented May 28, 1940 PATENT OFFICE MACHINE TOOL Fred A. Parsons,

Falk Corporation, tion of Wisconsin TRANSMISSION AND- NTROL Milwaukee, Wis., assignor to The Milwaukee, Wis., a corpora- Application December 18, 1936, Serial No. 116,469

29 Claims.

This invention relates to transmission and control mechanism, and more particularly for machine tools.

An object of the invention is to provide' an improved transmission mechanism, adjustable to effect any speed within a predetermined range, and particularly to effect such result in a manner to avoid variations in the ratio of input and output speeds, at a given speed adjustment, under different conditions of use, such as have been previously generally characteristic of friction or fluid operated rate changers by reason of slip or leakage, and especially to provide such transmission mechanism in a form suited for use in machine tools.

A further purpose is to provide an improved transmission in which rate changes are controlled by adjustment of engaged friction means in a manner such that changes in loading or other changes in operating conditions will not operate to cause variation in the rate selected, and particularly to provide such a rate changer in a form adapted for use in machine tools.

A further purpose is to provide an improved control mechanism in a form suited for the control of transmission mechanism such as previously mentioned, and especially for effecting a combined transmission and control mechanism adapted for machine tool use.

A further purpose is to provide transmission or control mechanism including some of the improvements previously mentioned and in a form to be particularly adapted for transmissions involving heavy pressure or torque, as for instance to efiect a positive drive for the cutting train of a machine tool.

Another purpose is to provide improved transmission reversing mechanism and control mechanism therefor and more especially where the transmission is driven from an electric motor, and particularly for machine tool transmissions.

An other purpose is to provide an improved combination of rate changer and reversing mechanism together with control mechanism such, for instance, that the start of a cycle of movement will be at a preferred rate, and the rate will subsequently be automatically changed to effect a rate preferred for the other portions of the movement.

Another purpose is to provide improved transmission and control mechanism for change of rate during reversal, together with improved means for effecting a gradual change from the one to another rate during a time period of selected duration.

A further purpose is to provide such mechanism for change of rate together with improved means for effecting the desired change at selected points in a cycle of movement, as for instance at either or both of the reversing points I at opposite ends of a reciprocatory cycle of movemen Another purpose is generally to simplify and improve the construction and operation of transmission and control mechanism, particularly for 10 machine tools, and more especially of planers, and still other purposes will be apparent from the specification.

The invention consists of the construction and combination of parts as herein illustrated, dell scribed and claimed, and in such modifications of the structure illustrated and described as may be equivalent to the structure of the claims.

The same reference characters refer to the same parts throughout, and in the drawings:

Figure l is a side elevation of a machine which incorporates the invention, the machine in this instance being a planer.

Figure 2 is a top or plan view of the same machine, partly in horizontal section taken ap- I proximately along the line 2-2 of Fig. 1.

Figure 3 is an enlarged horizontal section through a speed control or rate changer unit shown in Figs. 1, 2, the section being taken along line 2-2 of Fig. l.

Figure 4 is a vertical section through the unit shown in Fig. 3, taken along line 4-4 of Fig. 3.

Figures 5 and 6 are partial vertical sections through the same unit taken respectively along lines 5-5 and 6-6 of Fig. 3.

Figure 7 is a vertical section taken along line 1-1 of Fig. 3, and enlarged.

Figure 8 is a partial vertical section taken along line 8-8 of Fig. 2, and enlarged.

Figure 9 is a diagrammatic development of certain of the transmission and control mechanism of the machine, showing the operating relationship of various parts thereof.

Figure 10 is a diagrammatic development of certain control devices of the machine, particularly for start, stop and reverse of the main driving motor.

Figure 11 shows a modified portion of the rate changer shown in Fig. 3, in reduced size.

The machine here used to illustrate the invention is a machine tool of the type known as a planer, which includes a bed or base 20 which supports a work table or support 2| for reciprocation to right and left in Fig. 1.

Adjacent table 2| there is a tool support generally denoted by the numeral 22, which carries a tool 23 for adjustment relative to the table. In this instance the tool is carried on a clapper 24 for pivoting about a pivot 25 for relief of the tool during one direction of table movement, the clapper being carried by a support 25 for angular setting about a pivot 21, the support 23 being carried on slide 23 vertically adjustable on a saddle 23 which is horizontally adjustable above table II on a rail 35. Rail 35 is vertically slidably adjustable on supports, such as 3|, 3|, which are fixed with bed 20 at their lower end and extend upwardly respectively adjacent the opposite longitudinal edges of table 2i.

The guide or slide means for the various supports, as well as means for adjusting and for rigidly fixing certain of the support members in adjusted position, being well known in various forms for a machine such as here shown is not here shown or described in detail, and it will be understood, may take a variety of forms.

For the movement of table 2| there is provided a power source, in this instance an electric motor 32, which is connected to drive the table through a transmission including the motor shaft 325, a coupler 33 of any suitable form, a shaft 34, pinion 35, gear 35, shaft 31, a differential device generally denoted by the numeral 33, a shaft 33 co-axial with shaft 31, and a worm ll engaging a suitable rack 41 which is fixed to the underside of table 2| to extend substantially the full length thereof between the table slides or guides 42, 43.

The differential device 38 includes, in this instance abevel gear 44 fixed on shaft 31, a bevel gear 45 fixed on shaft 33, a cage or carrier member 45 which is independently rotatable coaxially with shafts 31, 39, and bevel gears l1, 33 each independently rotatably carried by cage 45 and each simultaneously engaging gears ll, 45. Fixed with cage 46 there is a worm wheel 43. which is engaged by a worm 50, Fig. 8, fixed on a shaft The cage 45 of the differential 33 is connected from motor 32 through a transmission which includes a bevel gear 52 fixed on shaft 31, a pinion 53, a shaft 54, a clutch device generally denoted by the numeral 55, a speed control or rate changer unit generally denoted by the numeral 55, having a driving shaft 51 and a variable speed driven shaft 58, and bevel gears 55, 50, the last mentioned gear being fixed on the shaft 5| to drive the cage 43 through the worm 50, Fig. 8, and wheel 49.

The speed control or rate changer unit 55, as here shown, is of a construction disclosed in the co-pending application Serial No. 52,095, filed November 29, 1935, and will therefore here be only briefly described. The rate changer includes the drive shaft 51, a driving gear 5| fixed on the drive shaft, a driven gear 52 fixed on the driven shaft 53, which is co-axial with shaft 51, and gears such as 63 fixed on shafts such as 54, there being several of the gears 53, preferably three, equi-angularly spaced and each simultaneously engaging the driving gear II and driven gear 32. Shafts I are each journaled in a cage. generally denoted by the numeral 55, which is supported for independent rotation co-axial with drive shaft 51, the cage including a sleeve portion 550 and flange portions 55b and .50 fixed with sleeve 55 and respectively carrying the bearings for the opposite ends of shafts 53, in this instance anti-friction bearings such -as 55, 51.

Fixed for rotation or integral with each of shafts 54 are conically tapered friction rolls such as 83, the axis of the shafts 64 being angularly disposed with respect to the axis of drive shaft 51, at an angle such that the outerperiphery of each of the conical rolls is parallel with the axis of drive shaft 51. Frictionally simultaneously engaging the peripheries of each of the rolls 65 there is a non-rotatable friction ring 89 carried by a frame generally denoted by the numeral 15, the frame together with the ring 59 being adjustable in a path parallel with the axis of drive shaft, whereby to engage ring 69 with the rolls 58 at points of different roll diameter, the frame being slidably guided for such movement on spaced guide members or rods 1 I, 12, to be shifted by means later described. Ring 69 is prevented from rotation and carried by frame in a manner permitting of a certain amount of adjustment relative to the frame whereby to simultaneously engage the periphery of each of the friction rolls 68 with equal pressure and at corresponding roll diameters, but since the details of the ring mounting do not concern the present invention they will not be here described.

The friction contact between the rolls 68 and ring 69 forces each roll and its companion gear 63 to revolve whenever cage 55 is revolved and at a roll speed determined in part by the diameter of rolls 68 at the point of ring contact. As the ring 89 is axially shifted it contacts rolls S8 at points of difierent roll diameter and changes the relative speed of the rolls. Thus as the ring is adjusted to the right in Fig. 3 the speed of rolls 68 and of the gears 53 increases, and vice versa, and the relationship of the various parts of the rate changer is such that when shaft 51 is driven at a constant speed the variable speed of rolls 68 will enforce a variable speed on driven shaft 58. With the parts proportioned as shown in Fig. 3 the speed of driven shaft 58 may be any speed from zero speed, obtained when ring 69 is nearly in its farthest position to the right, to a maximum speed which is somewhat less than the speed of drive shaft 51, depending on the ratio of the gearing between shafts 51, 58, the ratio of the smallest and largest diameters of rolls 68, etc., but by suitably proportioning the parts the shaft 58 may pass through the zero speed and be driven reversely in the right hand position of ring 69. But in any event any speed within the range determined by the proportioning of the parts of the rate changer, either forward or reverse. may be obtained by adjustments of ring 69 to intermediate positions.

Means are provided to maintain suitable friction pressure between the rolls 68 and ring 69. For this purpose the bearings 65, 51 are mounted to be unitarily axially slidable along their axes with rolls 58. Each of the rolls is continuously urged to the right in Fig. 3 by the means of a yoke 13 slotted as at 14. Fig. 5, to provide ears such as engaging a sleeve, such as 16, which carries the bearings 51, the yoke 13 being continuously urged to the right in Fig. 3, together with the sleeves, bearings and rolls, by the means of a spring 11, the spring pressure being adjustable by the means of a spring abutment member 18 threaded on the hub 19 of yoke 13. Forcing the rolls 58 to the right maintains friction pressure between the roll periphery and the friction ring 59 by reason of the angular relationship of the axes of shafts GI and the relationship of th parts is such that in addition to the pressure of spring 11 an additional pressure, depending on I manages the load carried by the rate changer also operates to force the rolls to the right.

Rotation of the cage 48 of the differential device 88 at different rates determined by rate changer Bl changes the speed of the table drive worm 40 and hence the cutting speed of table 2!. Thus when the rate change device II is set for zero speed, whereby cage II is stationary, and with the differential bevel gears of equal size, as here shown, the worm II is driven at the same speed as gear 3 and shaft 31. But assuming that cage 48 is rotated at suitable speed and in proper direction then shaft 3! and worm ll would not rotate and table 2| would be stationary. In the present instance, however, it is preferred to use other means for stopping the table 2| as will be later described. But it is obvious that any desired maximum table speed may be obtained by suitably proportioning the gearing of the transmission connecting the motor 32 to the table through the differential 38 to eifect the desired maximum when the cage 40 is stationary, and that any desired minimum table speed may be obtained by suitably proportioning the transmission connecting the motor 32 to the cage ll through the rate changer Ii toefiect the cage speed required for that minimum table speed at the time when the driven shaft 58 of rate changer 58 is rotating in the proper direction at maximum speed. I

In other words the adjustment of rate changer St for minimum speed of its output shaft ll may effect the maximum table speed, the rate changer adjustment for maximum speed of its output shaft 58 may effect the minimum table speed, and any table speed intermediate such maximum and minimum may be obtained by adjusting the control ring of rate changer 58 to a suitable intermediate position.

One of the characteristics of the transmission thus far described is that the drive from motor 32 to output shaft 39 and table 2! is positive, although the rate changes effected by the rate changer 56 are effected by adjustment of elements only frictionally engaged. This is because the rate changer output shaft is. connected to the cage 46 of differential 3! through a train which is inherently self-locking. In this instance the self-locking feature is obtained by worm SI and worm wheel 40. By reason of this construction torque exerted on the cage 46 by motor 32 cannot operate through worm wheel 49 to affect or alter the output speed of the rate changer. Moreover, if the transmission is so arranged, as in the device of Fig. 3, that the worm SI always tends to rotate the difierential cage ll in the same direction in which the cage is urged by the motor 32, then the only power required to be transmitted through the rate changer it is that required to overcome the friction of the train extending from the rate changer drive shaft 51 to the worm 5|. In other words the rate changer, in such case, merely unlocks the worm wheel I! to permit cage ll to rotate at the speed determined by the rate changer. Under such conditions rate changer it may be of very small and compact dimensions as compared with transmissions where the rate changer is required to carry some or all of the transmission load.

The rate changer 56, as here shown includes a differential device, consisting of the co-axial driving gear ii and driven gear 62 and the gears 63 which connect the driving and driven gears and are carried by the independently rotatable co-axial cage 65. The rotational speed of the .3 cage is of such difierential device is determined by the adjustment of en aged friction elements consisting of the; tapered or conical mils II and the non-rotatable ring it.

Rate changer 50 may be modified in various being extended to engage the periphery of gear 62a. This form, or its equivalent, with suitable modification of other parts, may be preferred for various reasons. .Generally speaking the result of using a smaller output gear, such as 02a,

is to extend the range of the rate changer. with the various other parts proportioned as in Fig. 3 the construction of Fi8.-11 would alter the operation of the rate changer by effecting the zero output speed of shaft 50 at approximately the central point in the movement of ring Cl, andeffecting a considerably larger speed range, but divided between positive or forward speeds and negative or reverse speeds. The result of the reverse speeds would be to drive the output shaft 39 of differential 38 in the same direction as the;

forward speeds but at a higher speed than 'obtained when the output shaft 58 of the rate changer is at zero speed, the increase in speed of shaft 3! being in accordance with the value of the negative speed of shaft 5|.

It is also to be understood that various other forms of rate changer may be used, and sometimes may be preferred, such for instance as that shown in Patent No. 2,016,248, issued October 1-, 1935, in which a friction roller is adjustable to contact a friction disc at different disc diameters, the disc and rollers being suitably connected between shafts 5| and 51. Also any suitable hydraulic rate changer may be used.

Table 2| is reversed, for operation in either direction, and stopped, by suitably controlling the motor 32. In this instance motor 32 is a reversible direct current motor connectible with a line 80, Fig. 9, through a suitable controller, generally indicated by the numeral ll, Fig. 9, which is operated by switch means generally denoted by the numeral 82, Fig. 9. The controller is also diagrammatically indicated in Fig. 10 as will be later explained. A motor directiomfor left hand movement, Fig. 9, of the table is effected when a movable member 83 of switch 02 engages a switch contact II, and for a right hand table movement when switch member 03 engages a contact ll, there being an intermediate position of member 83, as shown in Fig. 9 in which motor 32 is movement of the switch member 83 through a connecting rod II, a pivoted lever N, a connecting rod 80, a lever 9| fixed on a shaft 92 and a lever 93 also fixed on shaft 92 and carrying the switch member ll.

The reversing switch I! may also be operated by table dogs, such'as M, ii, Fig. 9. respectively operative in different planes for contact withdifferent trip members SI, S1 in the different directions of table travel, the trip members being each pivoted on the upper end of lever 81 and in different planes corresponding to the planes of the dogs, the members 9, 91 each being prevented from movement relative to lever '1 in one direction by abutments such as "a, 91s, whereby to move the lever II, in the one direction of dog movement, but permitting each trip member to pivot in the opposite direction to permit the dog to pass the trip member without movement of the lever 61. A detent cam device 81a. of usual construction operates to hold the lever 61 and switch 82 in central position if desired, but effects a quick shift of the parts to effect opposite engagement of switch 02 during shifting out of either engagement by the dogs 64, 35.

In normal operation dogs 94, will cause table 2| to be automatically reversed at each end of a table cycle in which the length of table stroke is determined by the dog spacing, but either trip member 30, 01 may be manually moved about its pivot to avoid the dog, whereby to permit operation of hand lever 06 for eflecting a table stop at either end of the table stroke.

Cutting tools such as shown at 23 in Fig. 1, when used in a planer, are intended for cutting only with the table moving in a certain direction, as to the right on Fig. 1. In such case the left hand or non-cutting movement may be much faster. But with other well known forms of machine tools, or with planers as here shown, provided suitable cutting tools are used, the table may be required to operate at a cutting rate in both directions of table movement. In any case, and particularly in planers, the maximum cutting rate may be considerably increased if the tool is permitted to contact the work at a relatively slow rate to avoid shock. Afterwards the rate may be increased to a maximum determined by the nature of the work and cutting tool. Means whereby a cutting rate may be selectively effected in one or both directions, and the cutting rate accelerated following work engagement at either or both ends of the table stroke will now be described.

The rate changer 56 is driven through a clutch device 55, as previously stated. Clutch device 55 includes an inner member 08, Figs. 3, 7, fixed on shaft 54, and an outer member 99 fixed on shaft 51, the inner member having a plurality of cam surfaces such as 36a each provided with spring pressed rollers such as 98b. This construction provides an overrunning clutch device operative for shaft 51, rate changer 56 and differential cage 46 to be driven from motor 32 only in one direc-- tion of motor rotation and table travel, which in this instance would be the normal direction for a planer tool such as 23, that is to say to the right in Fig. 1. In the other direction of table travel the rollers 931) will not drive the rate changer and differential cage. If the train connecting the rate changer 50 to the cage 46 is nonreversible, which, as previously explained, may be effected by self-locking characteristics of the worm 50, then in said other direction of table travel the cage 46 will be held stationary, since gear 46 cannot drive worm 50. As previously explained, with rate changer 56 constructed, as shown in Fig. 3, cage 46 is stationary when the table speed is greatest, and the idle or return speed of the table, following the reversal of the driving motor to effect left hand table movement will therefore, when the overrunning clutch is operative, be the maximum speed available from the table drive.

But clutch device 53 is also provided with means locking shaft 51 to rotate with shaft 54, whereby to render the overrunning clutch inoperative in either direction of motor rotation. Thus the outer member 99 is provided with exterior clutch teeth 39a engageable by complimentary clutch teeth on the inner rim of a clutch member I00,

which is slidably splined on shaft 54. Clutch member I00 may be shifted to engage with the teeth 99a of member 96 by the means of a hand lever I0l, Fig. 1, having an end portion (not shown) suitably engaging an annular groove iIIla, Fig. 3, in the clutch member. When the clutch members 80, I00 are engaged the rate changer 50 will control the table rate in each direction, because the worm 50 then drives the differential cage 56 similarly in both directions, and the selflocking characteristics are not effective upon reversal. Table 2I will then operate at a cutting rate controlled by rate changer 56 in both directions of its travel.

As previously explained the rate of the output shaft 58 of rate changer 56 and of the differential cage 46, which determines the speed of table 2I during a cutting stroke, is controlled by the axial adjustment of the non-rotatable ring 69, Fig. 3v Ring 69 may be positioned at any point in its 'range by suitable adjusting means, in this instance abutment screws I02, I03, adjustable to abut a shifter fork member I04 which engages the ring carrying frame 10. Except as it is desired to accelerate the cutting speed of the table following reversal, as for instance to first cont-act the work at a slower speed and to then increase the speed to the maximum which the work and tools will stand, as previously mentioned, the abutment members I02, I03 may be adjusted to lock ring 69 in any desired cutting speed position.

But if it is desired to accelerate the speed, as at the start of a cutting stroke, or for similar reasons, the screw I03 is adjusted to the position productive of the desired maximum cutting speed when fork I04 contacts that screw, and the screw I02 is adjusted to the position productive of the desired minimum speed. In other words the abutment screws I02, I03, are spaced apart an amount determined by the difference in the minimum and maximum desired speeds.

Mechanism is provided to shift the speed control ring 69 from the high speed to the slow speed positions upon reversal at either or both ends of table movement, followed by a gradual shifting to return ring 69 to the position of maximum cutting speed, the time required to effect the change from minimum to maximum cutting speed being controlled by manually adjustable means. Such mechanism is as follows:

Shifter fork I04 is shiftable by a piston device I05, Fig. 3, which includes a piston I06, a cylinder I01 and a piston rod I08, upon the end of which shifter fork I04 is fixed, and a larger piston rod I08a extended through the other end of the cylinder. Fluid for operation of piston device I05 is supplied from a pump I00, Fig. 9, preferably driven at constant speed from motor 32 through any suitable transmission line IIO, a portion of which is diagrammatically indicated in Fig. 9. Pump I09 supplies a pressure line III, which should be continuously supplied when the machine is operating, and since the motor 32 is reversible to effect the table reverse, as previously described, the pump I09, when driven from motor 32 is of the type which delivers fluid in the same direction irrespective of the direction of rotation of its drive shaft. Since this result is merely a matter of suitable passages and check valves within the pump casing, and any suitable well known form of pump may be used the pump is not shown in detail. Pump I00 may also be driven at constant speed from a separate uni-direction source such, for instance, as another motor. Between the pump I00 and supply line III there is a suitaaoaaes 5.

able pressure limiting valve H2 and an accumulator device IIO, bothof which may be of any well known form. Pump I draws fluid from a sump or reservoir III, Fig. 9, and all waste fluid I such as leakage or outflow of fluid from any of the parts connected with the pump is returned to reservoir I I0 by suitable channels or conduits (not shown).

The right face of piston I00, Fig. 9, is continuously supplied with pressure fluid directly from the pressure channel III through a channel 5 The left face is supplied with fluid through a channel 0 controlled by a valve 1. Valve 1 provides a plunger IIO, an outlet port 0 connected to channel 5, an inlet port 0 connected to channel I I0, an inlet port I connected to supply channel III through channels I2I, I22 and a drain port I20. In the right hand position of valve plunger I I0, as shown in Fig. 9, the chan- Ii nel H0 and port 0 connects the left end of piston I00 of piston drive I00 to the drain port I20 through an annular groove I20 in the plunger and the rate changer speed control ring 00 is then shifted to the left by pressure in channel II5 ll until shifter fork I00 abuts the screw I02, thereby reducing the speed of table 2|, in an amount determined by the adjustment of screw I02. In the left hand position of valve plunger IIO the pressure port I20 is connected through groove an I24 to the outlet port H0 and through channel iii to the left end of piston I00, and in this case since the left end of piston I 00 has the largest effective area by reason of the smaller piston rod I00, the piston I05 and speed control ring 00 00 will move to the right, in a direction to increase the speed of table 2| in an amount determined by the adjustment of screw I00.

The plunger 0 has a smaller piston end I25 and a larger piston end I20, respectively, supplied with pressure fluid from pressure channel |I| through'a port I21 and a port I20. Fluid supply to the large piston end I20 passes through a needle .valve device I20 in which an opening I00 is controlled by adjustment of a screw IOI. From the cylinder portion enclosing the piston end I20 a port I02 and channel I00 connects the cylinder to poppet valves I04, I05 respectively through shut off valves I00, I01, the valves I00, I05 being respectively opened in the opposite directions of to movement of reversing switch 02, there being a valve actuating member I01, flxed on the switch shaft 02, which carries pivoted latch dogs or cam elements I00, I00 each spring urged against stops I00 or III. v Assuming that shut ofl' valves I00, I01 are both open, then in the one direction of movement of shaft 02 and reversing switch 02, the outer end of dog I00 will force the plunger of poppet valve I05 outwardly to open the poppet valve for a 00 period during the switch movement, the poppet valve passing the dog end to permit the valve to close again. While the poppet valve is open the pressure is drained from plunger end I20 of con-- trol. valve II 1, and pressure against the plunger 05, end I25 forces the plunger 0 to the right in Fig. 9, thereby connecting the left end of a piston I00 to the drain I20, whereby the piston I00 and speed control ring 00 moves to the left to reduce the table speed to the point determined by the "I adjustment of abutment screw I02, as previously described. However, as soon as the poppet valve closes again, which occurs at or about the time the reversing switch reaches its position for eflecting the reverse table stroke, then fluid pressure begins to build up against the piston end I20 of plunger IIO, fluid passing through the needle valve device I20 at a ratedetermined by the adjustment of screw IOI, and eventually, at a point in the reverse table stroke determined by the needle valve adjustment, the plunger I I0 moves to the left again 5 sufficiently to again connect the left end of piston I00 to pressure fluid through the ports IIO, I20 of valve 1, whereby to againmove piston I00, and speed control ring 00 in the direction to increase the tablespeed to the point determined 10 by the adjustment of abutment screw I00.

When-the switch 02 is next again shifted to reverse the table stroke the poppet valve I05 is not opened during the reverse switch movement,

the pivoted latch dog I00 then swinging to pass 15 over the end of the poppet valve plunger without movement of the plunger. But during this reverse movement of the switch the other poppet valve I00 is operated by latch dog I00 in a manner corresponding to that just described for the pop- Q pet valve I05, whereby in the table reversal then eflected there will be a similar start of opposite table movement at slow rate and a subsequent increase of table speed to the speed determined by the position of abutment screw I00. 85.

Operation of the slow starting and speed increase means requires that the shut of! valves I30, I01 be open, since otherwise no fluid can leak through the pop t valves to permit move ment of valve plunger IIO to the right. Closing 00 one or the other valve I00, I01 prevents the operation of the speed reducing and accelerating means at the stroke end controlled by the corresponding Poppet valve, and since the speed control ring then remains in the position contacting the abut- 35? ment screw I02 the reverse at that end is then effected at the higher speed determined by screw I02. Thus according to the adjustment of valves I00, I01 the slow start may occur at either or both ends of the table stroke. But it is to be noted that, in any event, when hand lever III is in the position rendering effective the overrunning clutch mechanism of clutch device 55, the speed reducing and accelerating mechanism will only be effective at the start of the cutting stroke oi l the table.

-While the mechanism just described will ordinarilyi be operative for a suiiiciently gradual movement of speed control ring from slow to high speed position, and the rate of such movement can ordinarily be sufficiently controlled by adjustment of the needle valve I20, provided that the parts involved are suitably proportioned, yet it is sometimes preferable to supplement the device by the addition of an adjustable needle valve I I02, Fig. 9, in the channel IIO leading to the left end, Fig. 9, of .piston I00. Needle valve I02 includes an aperture I00 adjustable by a screw I, through which fluid passes to piston I00. By suitable adjustment of needle valve I02 this valve may supplement the action of needle valve I00 to effect any desired rate of increase of speed following table reversal to effect a cutting stroke.

The reverser controller 0| and switch 02, Fig. 9, is shown in simplified diagrammatic form in Fig.

10, in which, it will be understood, only certain essential functions are indicated and various supplemental portions, not essential, are not shown. As there shown the main power line 00 is connectible to the field 0Ia of motor 0| through a stop and run switch I05, and to the rotor 0"; of the motor through both the switch I40 and a switch I00.

Switch I05 includes the live contacts I01, I00,

which may be shifted to engage the contacts I40, 75

Ill. respectively, there being a switch member Ill continuously urged by a spring I52 in a direction to open switch I45, but which may be urged in the other direction, to close switch I45, by means of a solenoid I52a.

Switch I45 is manually controlled to close the switch by means 01' a normally open switch I53, which may be closed by a push button I54 whereby to complete the circuit oi! solenoid I52a. The resulting movement of switch member I5I closes a switch I55 and the circuit of solenoid I52a is then closed through switch I55 and a normally closed push button switch I55, following which the push button switch I53 may be released and switch I45 will remain in closed position until such time as a push button I51 is operated to open the switch I55, whereby to interrupt the circuit of solenoid III and permit spring I52 to again open switch I44. By the mechanism described the main switch I45 may be closed by manually operating the push button I54 to effect a run position and will remain closed until push button I5! is manually operated to effect a stop" position. At all times when main switch I45 is in run position the machine may be operated and controlled from reversing switch 52 as previously described. The engagement of contacts 84, 85 by the contact 43 of the reversing switch respectively close the circuits of solenoids I58, I59 of switch I45 for shifting a switch member ISO in opposite direction, whereby a series of contacts ,III, I52 operate to correspondingly reverse the polarity of the motor rotor 32b relative to the field 32a. When contact 83 is disengaged from both contacts l4, 85 the member ISO is positioned centrally by suitable means such as a spring operated detent device I53 operating on suitable cam surfaces "is, thereby cutting oil? line current to rotor 32b to stop the motor. For quickly manually bringing the table to a stop the switch 82 may momentarily be thrown to reversing position, and then brought back to the central position. To assist in bringing the table to a stop, or in slowing down the motor to assist reversal, the motor armature may be short circuited during the intermediate portion of the movement of switch 52, as by a short circuiting switch I631) or other suitable means, which is opened to provide the reversing switch operation previously described whenever switch 82 is in either closed position.

What is claimed is:

1. In a machine tool the combination of relatively movable supports, transmission mechanism I for actuation of one of said supports including a diflerential device, said diflerential device including a member simultaneously peripherally and bodily rotatable, a rate changer connected or adjustably efiecting various rates of said bodily member rotation, reverser means connected .i'or simultaneous reversal of said diiierential device and rate changer, power means for adjustment of said rate changer, and means controlling said power means in accordance with operation 01 said reverser means.

2. In a machine tool the combination of relatively movable supports, transmission mechanism for actuation oi one of said supports including a diiIerential device, said differential device including a member simultaneously peripherally and bodily rotatable, a rate changer connected for adiustably eflecting various rates of said bodily member rotation, reverser means connected for simultaneous reversal of said differential device and rate changer, means for adjustment of said rate changer, means for adjustment of said reverser, and control means selectively operable for substantially simultaneous adjustment of said rate changer and reverser or for independent ad- Justment or said reverser.

3. In a machine tool the combination of relatively movable supports, transmission mechanism for actuation of one oi said supports including a power source and a diirerential device, said diflerential device including a member simultaneously peripherally and bodily rotatable, and a rate changer connected to be driven from said source and for adjustably effecting various rates of said bodily member rotation, the connection oi said rate changer including an overrunning clutch device for driving the rate changer and means preventing transmission of power from said diii'erential device reversely to said rate changer.

4. In a machine tool the combination of a reciprocatory support, a transmission therefor including a diflerential device, said differential device including a member simultaneously peripherally and bodily rotatable, a rate changer connected for adjustably effecting various rates of said bodily rotation of the member, the connection of said rate changer including means preventing transmission of power from said dlflerential device reversely to said rate changer, and shiitable reversing means operable for reversal of said differential device, said reversing means eflecting disconnection of the drive to said rate changer.

5. In a machine tool the combination of a reciprocatory support, a transmission therefor including a differential device, said differential device including a member simultaneously peripherally and bodily rotatable, a rate changer connected for adjustabiy efiecting various rates of said bodily rotation of the member, the connection of said rate changer including means preventing transmission of power from said differential device reversely to said rate changer, shiitable means operable for reversal of said diiferential device and substantially simultaneously disconnecting said rate changer, and dog controlled trip means operative in accordance with the reciprocatory movement oi said support for shifting said shiitable means.

6. In a machine tool the combination of a reciprocatory support, a transmission therefor including a difierential device, said differential device including a member simultaneously peripherally and bodily rotatable, a rate changer connected for adjustably effecting various rates of said bodily rotation of the member, the connection of said rate changer including means preventing transmission of power for said differential device reversely to said rate changer, shiitable reversing means operable for reversing said differential device, and means alternatively adjustable i'or connecting said rate changer for reversal simultaneously with said device or disconnecting said rate changer during reverse rotation of said device.

7. In a machine tool the combination of relatively movable supports, transmission mechanism for actuation of one of said supports including a difi'erential device, said dliferential device including a member simultaneously peripherally and bodily rotatable, a rate changer connected for adJustably effecting various rates of said bodily member rotation, means for adjustment of said rate changer, and dog controlled trip means controlling the operation of said adjusting means in accordance with the movement of said support.

8. In a machine tool the combination relatively movable supports, transmission mechanism for actuation oi one of said supports including a differential device, said diflerential device ineluding a member simultaneously peripherally and bodily rotatable, a rate changer connected for adjustably eil'ecting various rates of said bodily member rotation, reversing means for said transmission, independently operable controller devices respectively for adjustment of said rate changer and for operation of said reversing means, and other control means operable for substantially simultaneous operation of said reversing means and adjustment of said rate changer.

I 9. In a machine tool the combination of relatively movable supports, transmission mechanism for actuation 01' one of said supports including a diflerential device, said diii'erential device including a member simultaneously peripherally and Q bodily rotatable, a rate changer connected for adjustably eiiecting various rates of said bodily member rotation, reversing means for said transmission, independently operable controller devices respectively for adjustment of said rate changer and for operation of said reversing means, other control means operable for substantially simultaneous operation or said reversing means and adjustment of said rate changer, and means controlling the grate of adjustment of said rate I changer upon operation of said other control means.

10. In a machine tool the combination of relatively movable supports, transmission mecha-- nism for actuation of one of said supports including a diiierential device, said difl'erential device including a member simultaneously peripherally and bodily rotatable, a rate changer connected for adjustably eflecting various rates of said bodily member rotation, reversing means for said trans- Q mission, independently operable controller devices respectively ior adjustment of said rate changer and for operation ,of said reversing means, and other means for adjustment of said,

rate changer including a fluid operable shifter I device and valve means controlling the operation of said shift device in accordance with the operation of said reverser device.

11. In a machine tool the combination of rela-- tively movable supports, transmission mechanism I for actuation of one of. said supports including an adjustable mechanical rate changer and a reversible electric motor, reverser means for said transmission, including a reverser switch device and a reverser controller for said motor operative I in accordance with the adjustment of said switch device and means for adjustment of said rate changer in accordance with the operation of said switch device.

12. ms machine tool the combination of relatively movable supports, transmission mechanism ,i'or actuation of one of said supports providing a differential device including a member simultaneously peripherally and bodily rotatable, a rate changer connected ior adjustably eii'ecting U various rates of said bodily member rotation, re-

verser means connected for simultaneous reversal of said difierential device and rate changer, said reverser means including a reversible electric motor, a reverser switch device and a reverser controller for said motor operative in accordance with the adjustment of said switch device, and means for adjustment of said rate changer in accordance with the operation of said switch device.

13. In a machine tool, the combination of relatively movable supports, transmission mechanism for actuation of one of said supports, including a difierential device providing a member si multaneously peripherally and bodily rotatable and a rate changer adjustabiy connected for etiecting various rates'oi' said bodily member ro- 6 tation, the connection of said rate changer and member including means preventing tra of power from said member reversely through the connection to said rate changer, reverser means for said actuated support. independently l operable controller devices respectively for said reverser and for adjustment of said rate changer, and means operable for rendering said rate .changer ineflective in one direction oi movement of said actuated support. l5

14. In a machine tool, the combination of relatively movable supports, transmission mechanism for actuation of one of said supports, including a differential device providing a member simultaneously peripherally. and bodily rotatable, a rate changer connected for eflecting various rates of said bodily member rotation, the connection of said rate changer and member including means preventing transmission of power from said member reversely through said connection, reverser means for said actuated support, independently operable controller devices respectively for said reverser means and for said rate changer, means rendering said rate changer inefiective in one direction of movement of said actuated support, and dog controlled'trip means for operation oi said reverser controller in accordance with the movement of said actuated support.

15. In a machine tool, the combination of relatively movable supports, transmission mechanism 86 for actuating one of said supports, including a differential device providing a member simultaneously peripherally and bodily rotatable, a rate changer connected for eflecting various rates of said bodily member rotation, the connection of 40 said rate changer and member including means preventing transmission 01' power from said member reversely through said connection, reverser means for said actuated support, independently operable controller devices respectively for said reverser and for said rate changer, dog controlled trip means for operation of said reverser controller in accordance withthe movement of said actuated support, and means adjustable for ren dering said rate changer ineflective in one di- 80 rection of support movement, said adjustable means being alternatively adjustable for rendering said rate changer effective in both directions of support movement.

16. In a transmission and control mechanism 66 the combination of a power transmitting diiierential device including a member having simultaneous bodily and peripheral rotation, another differential device providing an element having simultaneous bodily and peripheral rotation, rate 00 change means controlling the rate of bodily rotation of said element, and a motion transmitting connection from said other differential device for controlling the rate of bodily rotation of said member. 06

17. In a transmission and control mechanism the combination of a power transmitting diiierential device including a member having simultaneous bodily and peripheral rotation, another diflferential device providing an element having 70 simultaneous bodily and peripheral rotation, rate change means controlling the rate of bodily rotation of said element, and a motion transmitting connection from said other diflerential device for controlling the rate of bodily rotation of said 15 member, said motion transmitting connection including means preventing power transmission from the first mentioned differential device reversely to said other differential device.

18. In a transmission and control mechanism the combination of a power train including a power source, a driving gear, an intermediate gear and a driven gear in series in the order recited, said intermediate gear being bodily rotatable for changing the relative rates of said driving and driven gears, a branch train for determining said relative rates including in the order recited said power source, a driving element, an intermediate element simultaneously bodily and peripherally rotatable, a driven element and a motion transmitting connection from said driven element for bodily rotation of said intermediate gear, said motion transmitting connection being self-locking against transmission of power reversely therethrough, and rate change means adjustably controlling the rate or bodily rotation of said intermediate element.

'19. In a transmission and control mechanism, the combination of a main transmission including h a pair of bevel gears serially arranged and an intermediate bevel gear simultaneously engaging the gears of said pair and bodily rotatable, and a supplemental transmission including a rate changer, a worm and a worm wheel serially arranged, said worm wheel being connected for said bodily rotation of the intermediate bevel gear; said rate changer including a conically tapered roller bodily rotatable on an axis ofiset from the axis of its cone and a ring member coaxial with said ofi'set axis and internally engaging said roller, said roller and ring member being relatively adjustable axially of said ofiset axis.

20. In a machine tool the combination of relatively movable supports, transmission mechanism for movement of one of said supports including a shiitable rate changer and shiitable reversing means, power means for shifting said rate changer, control means for said power means operable to effect a gradual increase or rate to a predetermined maximum rate following a shifting of said reversing means, and means adjustably controlling the period or said increase of rate.

21. In a machine tool the combination of relatively movable supports, transmission mechanism for movement of one of said supports including a shittable rate changer and shii'table reversing means, power means for shifting said rate changer, and control means for said power means operable to effect an abrupt reduction or rate substantially simultaneously with shifting of said reversing means and a gradual increase of rate to a predetermined maximum rate following said shifting.

22. In a machine tool the combination of relatively movable supports, transmission mechanism for movement or one of said supports including a shiftable rate changer and shittable reversing means, power means for shifting said rate changer, control means for said power means operable to eilect an abrupt reduction of rate substantially simultaneously with shifting of said reversing means and a gradual increase or rate to a predetermined maximum rate following said shifting, and means adjustably controlling the period of said increase of rate.

23. In a transmission and control mechanism the combination of transmission mechanism including a rate changer comprising rate change elements frictionally engaged and relatively adjustable to different positions respectively eflecting relatively low and high speeds, said elements being relatively adjustable to any position intermediate said diiierent positions whereby to effect any intermediate speed, rate changer control means adjustably determinative of one of said speeds, power operable shifting means for relative adjustment of said elements to a position determined by said rate changer control means, and means preventing an abrupt shifting of said rate changer elements.

24. In a transmission and control mechanism the combination of transmission mechanism including a rate changer comprising rate change elements frictionally engaged and relatively adjustable to different positions respectively eiIecting relatively low and high speeds, said elements being relatively adjustable to any position intermediate said different positions whereby to effect any intermediate speed, rate changer control means adjustably determinative of one of said speeds, power operable shifting means for relative adjustment of said elements to a position determined by said rate changer control means, means preventing an abrupt shifting of said rate changer elements, and means controlled by said transmission for initiating the operation of said shifting means.

25. In a transmission and control mechanism the combination of transmission mechanism including a rate changer comprising rate change elements frictionally engaged and relatively adiustable to different positions respectively efiecting relatively low and high speeds, said elements being relatively adjustable to any position intermediate said diiierent positions whereby to effect any intermediate speed, rate changer control means adjustably determinative of one of said speeds, power operable shifting means for relative adjustment of said elements to a position determined by said rate changer control means, and means preventing an abrupt shifting of said rate change elements.

26. In a transmission and control mechanism the combination of a rate changer comprising a rotary carrier, a plurality of tapered relatively inclined planetary rollers rotatable with and with respect to said carrier, a non-rotating rate control ring encircling and frictionally contacting said rollers and axially shiftable to change the speed of the rollers, and control means for said rate changer including power means for said axial shifting of the control ring and means regulating the rate at which said power means may shift the control ring.

27. In a transmission and control mechanism the combination of a rate changer comprising a rotary carrier, a plurality of tapered relatively inclined planetary rollers rotatable with and with respect to said carrier, a non-rotating rate control ring encircling and trictionally contacting said rollers and axially shiftable to change the speed of the rollers, and control means for said rate changer including power means for shifting said control ring in either axial direction and means controlling the rate of operation of said power means during shiiting 'oi said ring in at least one of said directions.

28. In a transmission and control mechanism the combination of a rate changer comprising a rotary carrier, a plurality of tapered relatively inclined planetary rollers rotatable with and with respect to said carrier, a non-rotating rate control ring encircling and frictionally contacting 15 said rollers and axially shiftable to change the speed of the rollers, and control means for said rate changer including fluid operable means for shifting said control ring, a pressure fluid source connectible therewith, and means controlling the rate of pressure fluid flow from said source to said shifting means to prevent abrupt shifting of said ring.

29. In a transmission and control mechanism the combination of a rate changer comprising a rotary carrier, a plurality of tapered relatively inclined planetary rollers rotatable with and with respect to said carrier, a non-rotating rate control ring encircling and frictionally contacting said rollers and axially shiitabi to change the speed of the rollers, and control means for said rate changer including power means for said axial shifting of the control ring and means adjustably determinative of different rates of said axial shifting.

FRED A. PARSONS.

CERTIFICATE OF CORRECTION. Patent No. 2,202,265. a May 28, 191p.

. mm) A. masons.

It is hereby certified that errorappears in the'printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line 11, after "115" insert a period; line 211., before "pressure" insert -the--; line 39, afterPthe word "respectively" strike out the comma; same page, second column, line 61, for the reference numeral "159' read "129-"; page 6, second column, line 57, claim 6, for the word "for" read "frompage 7, first column, line [#6, claim 10, for "shift" read sb.ifter---; line 61, claim 12, for "providing" read --including--; line 62, same claim, for "including" read --providing--; same page, second column, line 56, claim 1 for the were "actuating" read --actuation of--;. and that the said Letters Patent should be read with this correction thereinthat the same may conform to the record of the case in the Patent Office.

Signed and sealed this Zhth day er September, A. D. 191w.

Henry Van Arsdale, (Seal) Acting Commissioner of. Patents. 

